Field of the Invention
The invention is directed to a voltage regulator and more particularly, to a low-dropout voltage regulator (LDO).
Description of Related Art
In applications of electronic apparatuses, particularly portable electronic apparatuses, users have increasingly high demand for battery life. If overall static power consumption can be reduced, the usage duration of a portable electronic apparatus can be effectively prolonged. The static power consumption is majorly induced by a low-dropout voltage regulator (LDO) installed in the portable electronic apparatus; however, the static power consumption of a typical LDO cannot be adjusted along with an output current.
Under this premise, if it is considered to design the LDO in a large-current application, the static state power consumption of the LDO is usually maintained within a range from 0.5 mA to 2 mA, and in this way, the demand for a longer standby duration of the portable electronic apparatus cannot be satisfied. On the other hand, if hardware parameters of the LDO are adjusted to lower down the static state power consumption (e.g., down to about 0.1 mA), it may lead to an issue of worse load transient response characteristics. As a result, an unrecoverable failure may occur during the process that the system is switched from the standby state to the operation state.